Browsing by Author "Namagambo, Barbara"

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    Emergence, Epidemiology, and Transmission Dynamics of 2009 Pandemic A/H1N1 Influenza in Kampala, Uganda, 2009–2015
    (The American journal of tropical medicine and hygiene, 2018) Cummings, Matthew J.; Bakamutumaho, Barnabas; Yang, Wan; Wamala, Joseph F.; Kayiwa, John; Owor, Nicholas; Namagambo, Barbara; Byaruhanga, Timothy; Lutwama, Julius J.; Shaman, Jeffrey; O’Donnell, Max R.
    In sub-Saharan Africa, little is known about the epidemiology of pandemic-prone influenza viruses in urban settings. Using data from a prospective sentinel surveillance network, we characterized the emergence, epidemiology, and transmission dynamics of 2009 pandemic A/H1N1 influenza (H1N1pdm09) in Kampala, Uganda. After virus introduction via international air travel from England in June 2009, we estimated the basic reproductive number in Kampala to be 1.06–1.13, corresponding to attack rates of 12–22%. We subsequently identified 613 cases of influenza in Kampala from 2009 to 2015, of which 191 (31.2%) were infected with H1N1pdm09. Patients infected with H1N1pdm09 were more likely to be older adult (ages 35–64) males with illness onset during rainy season months. Urban settings in sub-Saharan Africa are vulnerable to importation and intense transmission of pandemic-prone influenza viruses. Enhanced surveillance and influenza pandemic preparedness in these settings is needed.
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    Influenza-associated pneumonia hospitalizations in Uganda, 2013-2016
    (PLoS ONE, 2019) Emukule, Gideon O.; Namagambo, Barbara; Owor, Nicholas; Bakamutumaho, Barnabas; Kayiwa, John T.; Namulondo, Joyce; Byaruhanga,Timothy; Tempia, Stefano; Sandra, S. Chaves; Lutwama, Julius J.
    Background Influenza is an important contributor to acute respiratory illness, including pneumonia, and results in substantial morbidity and mortality globally. Understanding the local burden of influenza-associated severe disease can inform decisions on allocation of resources toward influenza control programs. Currently, there is no national influenza vaccination program in Uganda. Methods In this study, we used data on pneumonia hospitalizations that were collected and reported through the Health Management Information System (HMIS) of the Ministry of Health, Uganda, and the laboratory-confirmed influenza positivity data from severe acute respiratory illness (SARI) surveillance in three districts (Wakiso, Mbarara, and Tororo) to estimate the age-specific incidence of influenza-associated pneumonia hospitalizations from January 2013 through December 2016. Results The overall estimated mean annual rate of pneumonia hospitalizations in the three districts was 371 (95% confidence interval [CI] 323–434) per 100,000 persons, and was highest among children aged <5 years (1,524 [95% CI 1,286–1,849]) compared to persons aged ≥5 years (123 [95% CI 105–144]) per 100,000 persons. The estimated mean annual rate of influenza-associated pneumonia hospitalization was 34 (95% CI 23–48) per 100,000 persons (116 [95% CI 78–165] and 16 [95% CI 6–28] per 100,000 persons among children aged <5 years and those ≥5 years, respectively). Among children aged <5 years, the rate of hospitalized influenza-associated pneumonia was highest among those who were <2 years old (178 [95% CI 109–265] per 100,000 persons). Over the period of analysis, the estimated mean annual number of hospitalized influenza-associated pneumonia cases in the three districts ranged between 672 and 1,436, of which over 70% represent children aged <5 years. Conclusions The burden of influenza-associated pneumonia hospitalizations was substantial in Uganda, and was highest among young children aged <5 years. Influenza vaccination may be considered, especially for very young children.
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    The Correlation of IFN γ to the Preferential Isolation of Influenza Type B over Type A Viruses in Madin Darby Canine Kidney Cells
    (Open Journal of Medical Microbiology, 2017) Byaruhanga, Timothy; Bagaya, Bernard; Namulondo, Joyce; Kayiwa, John Timothy; Namagambo, Barbara; Owor, Nicholas; Nabukenya, Irene; Bakamuntumaho, Barnabas; Lutwama, Julius Julian
    The isolation of influenza viruses in Madin Darby Canine Kidney (MDCK) cells has shown preferential isolation of a great percentage of Influenza B strains at the first passage than Influenza A strains. During in vitro isolation of Influenza viruses, majority of type A viruses are not confirmed as positive isolates by Hemagglutination (HA) assay despite having higher virulence and pathogenicity versus influenza B viruses. This study investigated the differences in IFN-γ and IL-10 cytokines secreted by MDCK cells upon exposure to the viruses and thus provided possible answers as to why influenza type B can easily be isolated from MDCK cells compared to influenza A. Positive influenza viruses were inoculated onto MDCK cells. IFN-γ and IL-10 cytokines stimulated by the viruses in MDCK cells were measured by indirect ELISA at 1 hour, 12 hours, 48 hours and 72 hours post inoculation (pi). A total of 46 specimens, with 23 specimens from each virus type were analyzed. IFN-γ was significantly higher at 1 hour pi in MDCK cells for influenza type A at p value of 0.024 than type B. No statistical significance was observed in means of cytokine IL-10 between influenza type A and type B. The study may show that IFN-γ is correlated to the preferential isolation of influenza type B over type A viruses. Anti-inflammatory cytokines may not necessarily be playing a role in the preferential growth of influenza type B, a less virulent type over influenza type A in MDCK cells.